High-performance self-healing silicone elastomer enabled by dual-dynamic networks for flexible motion sensing

As application scenarios for flexible electronics and smart materials grow increasingly diverse and complex, conventional sensing materials frequently struggle to meet the escalating demands for both performance and functionality. In this study, a self-healing organosilicon elastomer (PHM-x) was developed by utilizing bis(aminopropyl)-terminated polydimethylsiloxane (PDMS-NH₂) as the soft segment and isophorone diisocyanate (IPDI) as the hard segment. Through the incorporation of 2,6-pyridinedimethanol (PDM) and N,N-bis(2-hydroxyethyl)oxalamide (BHO) as chain extenders, a multiple dynamic hydrogen bonding network was constructed within the polymer matrix. To further enhance the material’s performance, various metal ions, including Zn^{2 +} , Cu²⁺, and Fe³⁺, were introduced to form reversible metal-ligand coordination bonds, resulting in a dual cross-linking network. The synergistic interactions between hydrogen bonds and metal–ligand coordination significantly improved the mechanical properties of the elastomers, with PHM-Cu achieving a tensile strength of 5.76 MPa and a toughness of 17.20 MJ/m³. Moreover, the PHM-x elastomers exhibited outstanding self-healing capability, with healing efficiencies ranging from 80 % to 91 % at 80 ℃, as well as remarkable recyclability, maintaining over 95 % of their mechanical properties after three damage-healing cycles. Finally, by blending PHM-Fe with an ionic liquid, a flexible, self-healing sensing film was fabricated. This film demonstrated stable and sensitive signal output, capable of detecting diverse human motion behaviors, thereby offering a promising strategy for the design of next-generation multifunctional flexible electronic materials.